<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=0">
</head>
<body>
<script type="text/javascript">
var ua = navigator.userAgent.toLowerCase();
var isWeixin = ua.indexOf('micromessenger') != -1;
if (isWeixin) {
alert("abc");
}
</script>
this is abc
</body>
</html>
